Over the past few decades there has been vast monitoring of the worlds temperatures and a great many of those locales which have had their temperatures recorded have been seen to have increased mean temperatures. Averaged with the locations which showed little to no change in temperature over the years a startling trend was seen, thus recent fears over global warming were born, and coupled with visible effects seen in the environment, global warming is a real problem, and a real concern for most citizens.
The earth has warmed approximately 1 degree fahreinheit in the past century, glaciers are retreating on a global scale and sea-level has also risen. Combining this with the fact that through laboratory testing carbon dioxide has been proven to trap heat and that the presence of greenhouse gases in the atmosphere, especially carbon dioxide and methane, have been consistently rising, the two have been linked, with excessive greenhouse gases being blamed for warming of the earth and the effects that have been seen on the earth recently.
Global warming is caused by so-called "greenhouse gases", and occurs through the 'greenhouse effect." The gases to blame for this phenomenon include methane, carbon dioxide, nitrogen oxide and chlorofluorocarbons (CFC's, which also are to blame for ozone depletion). There are also natural causes for release of greenhouse gases into the atmosphere such as volcanic activity as well as sunspot activity (solar flares), as well as deforestation, which removes natural carbon sinks, thus allowing more carbon dioxide into the atmosphere rather than it being able to be absorbed by trees and plants so that it can be oxidized. For the most part, the release of such gases into the atmosphere in such copius amounts lies on the shoulders of humans, thus global warming is generally seen as caused by man, and unless man greatly reduces use of coal, gasoline in cars, and deforestation across the planet, earth will see even more detrimental effects in the future.
The Greenhouse effect that is blamed for global warming is necessary for the earth to maintain a livable temperature, but with excess greenhouse gases present in the atmosphere the green house effect causes global warming. These necessary greenhouse gases trap some of the outgoing energy that earth recieves from the sun, and it retains heat, much like how a greenhouse functions. When there are excess gases present in the atmosphere less and less energy can leave the atmosphere once it is reflected by the earth and is trapped, causing warming. Over time this excess gas which is trapped in the atmosphere causing warming creates visible effects on earth and its climate.
There have been several ecological changes in recent years that have been attributed to global warming. These include
1. Thawing of permafrost
2. Lengthening of the growing season in middle and high latitudes
3. Poleward and upward shift of plant and animal ranges
4. Decline of some plant and animal species
5. Earlier flowering of trees
6. Earlier emergence of insects
7. Earlier egg-laying in birds
All of these observations can be taken as proof of a warming earth, particularly the thawing of permafrost, poleward and upward shift of animal and plant ranges (due to a need for cooler temperatures) and lengthening of the growing season. There are many more examples of the profound effects global warming is having on our planet, and could potentially have, as well as further evidence of the chemical release into the atmosphere that is causing the warming of our planet, and all will be brought to light in this debate.
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